In my previous U.S. Pat. No. 3,401,576 which issued on Sept. 17, 1968, I disclosed a new and novel impact absorbing collapsible steering column for vehicles which utilized a pair of rod portions connected for conjoint rotation and sliding on each other for shortening and retaining the steering connection during a collision. An energy absorbing collapsible bellows device having metallic convolutes is attached to the two rod portions so as to cover the connection and is arranged to absorb impact energy applied to either end of the steering column by sequential collapse of the convolutes of the bellows.
The steering column according to the prior invention has been well received and accepted by the automobile industry. There have been other attempts in the past to provide other types of steering column assemblies which also can collapse if the vehicle in which the assembly is mounted is involved in a crash or collision. All of these are intended to minimize the risk of injury to the driver of the vehicle who in his vulnerable position is subject to intense injury and trauma by being impaled on the steering wheel shaft. To eliminate or mitigate this situation, it has been found necessary to allow the steering wheel column to move forwardly to cushion the forces created by the impact of the driver's chest and body against the steering wheel and column. By the same token, it is important that any impact with the front portion of the car, as during a collision, be isolated and prevented from being transmitted upwardly toward the driver. To accomplish all of this, it has been found necessary to provide some type of slip joint or impact absorbing device whereby the forces and energy which are applied to either end of the steering column will be successfully contained and restrained.